timestamp related functions added

timetype package include functions for calculating
time input in string as one of golang duration format and
calculate as unix timestamp

Signed-off-by: Kunal Kushwaha <kunal.kushwaha@gmail.com>

2 files changed, 226 insertions, 0 deletions

diff --git a/pkg/timetype/timestamp.go b/pkg/timetype/timestamp.go
new file mode 100644
index 000000000..eb904a574
--- /dev/null
+++ b/pkg/timetype/timestamp.go
@@ -0,0 +1,131 @@
+package timetype
+
+// code adapted from https://github.com/moby/moby/blob/master/api/types/time/timestamp.go
+
+import (
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// These are additional predefined layouts for use in Time.Format and Time.Parse
+// with --since and --until parameters for `docker logs` and `docker events`
+const (
+	rFC3339Local     = "2006-01-02T15:04:05"           // RFC3339 with local timezone
+	rFC3339NanoLocal = "2006-01-02T15:04:05.999999999" // RFC3339Nano with local timezone
+	dateWithZone     = "2006-01-02Z07:00"              // RFC3339 with time at 00:00:00
+	dateLocal        = "2006-01-02"                    // RFC3339 with local timezone and time at 00:00:00
+)
+
+// GetTimestamp tries to parse given string as golang duration,
+// then RFC3339 time and finally as a Unix timestamp. If
+// any of these were successful, it returns a Unix timestamp
+// as string otherwise returns the given value back.
+// In case of duration input, the returned timestamp is computed
+// as the given reference time minus the amount of the duration.
+func GetTimestamp(value string, reference time.Time) (string, error) {
+	if d, err := time.ParseDuration(value); value != "0" && err == nil {
+		return strconv.FormatInt(reference.Add(-d).Unix(), 10), nil
+	}
+
+	var format string
+	// if the string has a Z or a + or three dashes use parse otherwise use parseinlocation
+	parseInLocation := !(strings.ContainsAny(value, "zZ+") || strings.Count(value, "-") == 3)
+
+	if strings.Contains(value, ".") {
+		if parseInLocation {
+			format = rFC3339NanoLocal
+		} else {
+			format = time.RFC3339Nano
+		}
+	} else if strings.Contains(value, "T") {
+		// we want the number of colons in the T portion of the timestamp
+		tcolons := strings.Count(value, ":")
+		// if parseInLocation is off and we have a +/- zone offset (not Z) then
+		// there will be an extra colon in the input for the tz offset subtract that
+		// colon from the tcolons count
+		if !parseInLocation && !strings.ContainsAny(value, "zZ") && tcolons > 0 {
+			tcolons--
+		}
+		if parseInLocation {
+			switch tcolons {
+			case 0:
+				format = "2006-01-02T15"
+			case 1:
+				format = "2006-01-02T15:04"
+			default:
+				format = rFC3339Local
+			}
+		} else {
+			switch tcolons {
+			case 0:
+				format = "2006-01-02T15Z07:00"
+			case 1:
+				format = "2006-01-02T15:04Z07:00"
+			default:
+				format = time.RFC3339
+			}
+		}
+	} else if parseInLocation {
+		format = dateLocal
+	} else {
+		format = dateWithZone
+	}
+
+	var t time.Time
+	var err error
+
+	if parseInLocation {
+		t, err = time.ParseInLocation(format, value, time.FixedZone(reference.Zone()))
+	} else {
+		t, err = time.Parse(format, value)
+	}
+
+	if err != nil {
+		// if there is a `-` then it's an RFC3339 like timestamp
+		if strings.Contains(value, "-") {
+			return "", err // was probably an RFC3339 like timestamp but the parser failed with an error
+		}
+		if _, _, err := parseTimestamp(value); err != nil {
+			return "", fmt.Errorf("failed to parse value as time or duration: %q", value)
+		}
+		return value, nil // unix timestamp in and out case (meaning: the value passed at the command line is already in the right format for passing to the server)
+	}
+
+	return fmt.Sprintf("%d.%09d", t.Unix(), int64(t.Nanosecond())), nil
+}
+
+// ParseTimestamps returns seconds and nanoseconds from a timestamp that has the
+// format "%d.%09d", time.Unix(), int64(time.Nanosecond()))
+// if the incoming nanosecond portion is longer or shorter than 9 digits it is
+// converted to nanoseconds.  The expectation is that the seconds and
+// seconds will be used to create a time variable.  For example:
+//     seconds, nanoseconds, err := ParseTimestamp("1136073600.000000001",0)
+//     if err == nil since := time.Unix(seconds, nanoseconds)
+// returns seconds as def(aultSeconds) if value == ""
+func ParseTimestamps(value string, def int64) (int64, int64, error) {
+	if value == "" {
+		return def, 0, nil
+	}
+	return parseTimestamp(value)
+}
+
+func parseTimestamp(value string) (int64, int64, error) {
+	sa := strings.SplitN(value, ".", 2)
+	s, err := strconv.ParseInt(sa[0], 10, 64)
+	if err != nil {
+		return s, 0, err
+	}
+	if len(sa) != 2 {
+		return s, 0, nil
+	}
+	n, err := strconv.ParseInt(sa[1], 10, 64)
+	if err != nil {
+		return s, n, err
+	}
+	// should already be in nanoseconds but just in case convert n to nanoseconds
+	n = int64(float64(n) * math.Pow(float64(10), float64(9-len(sa[1]))))
+	return s, n, nil
+}
diff --git a/pkg/timetype/timestamp_test.go b/pkg/timetype/timestamp_test.go
new file mode 100644
index 000000000..0fffb85a9
--- /dev/null
+++ b/pkg/timetype/timestamp_test.go
@@ -0,0 +1,95 @@
+package timetype
+
+// code adapted from https://github.com/moby/moby/blob/master/api/types/time/timestamp.go
+
+import (
+	"fmt"
+	"testing"
+	"time"
+)
+
+func TestGetTimestamp(t *testing.T) {
+	now := time.Now().In(time.UTC)
+	cases := []struct {
+		in, expected string
+		expectedErr  bool
+	}{
+		// Partial RFC3339 strings get parsed with second precision
+		{"2006-01-02T15:04:05.999999999+07:00", "1136189045.999999999", false},
+		{"2006-01-02T15:04:05.999999999Z", "1136214245.999999999", false},
+		{"2006-01-02T15:04:05.999999999", "1136214245.999999999", false},
+		{"2006-01-02T15:04:05Z", "1136214245.000000000", false},
+		{"2006-01-02T15:04:05", "1136214245.000000000", false},
+		{"2006-01-02T15:04:0Z", "", true},
+		{"2006-01-02T15:04:0", "", true},
+		{"2006-01-02T15:04Z", "1136214240.000000000", false},
+		{"2006-01-02T15:04+00:00", "1136214240.000000000", false},
+		{"2006-01-02T15:04-00:00", "1136214240.000000000", false},
+		{"2006-01-02T15:04", "1136214240.000000000", false},
+		{"2006-01-02T15:0Z", "", true},
+		{"2006-01-02T15:0", "", true},
+		{"2006-01-02T15Z", "1136214000.000000000", false},
+		{"2006-01-02T15+00:00", "1136214000.000000000", false},
+		{"2006-01-02T15-00:00", "1136214000.000000000", false},
+		{"2006-01-02T15", "1136214000.000000000", false},
+		{"2006-01-02T1Z", "1136163600.000000000", false},
+		{"2006-01-02T1", "1136163600.000000000", false},
+		{"2006-01-02TZ", "", true},
+		{"2006-01-02T", "", true},
+		{"2006-01-02+00:00", "1136160000.000000000", false},
+		{"2006-01-02-00:00", "1136160000.000000000", false},
+		{"2006-01-02-00:01", "1136160060.000000000", false},
+		{"2006-01-02Z", "1136160000.000000000", false},
+		{"2006-01-02", "1136160000.000000000", false},
+		{"2015-05-13T20:39:09Z", "1431549549.000000000", false},
+
+		// unix timestamps returned as is
+		{"1136073600", "1136073600", false},
+		{"1136073600.000000001", "1136073600.000000001", false},
+		// Durations
+		{"1m", fmt.Sprintf("%d", now.Add(-1*time.Minute).Unix()), false},
+		{"1.5h", fmt.Sprintf("%d", now.Add(-90*time.Minute).Unix()), false},
+		{"1h30m", fmt.Sprintf("%d", now.Add(-90*time.Minute).Unix()), false},
+
+		{"invalid", "", true},
+		{"", "", true},
+	}
+
+	for _, c := range cases {
+		o, err := GetTimestamp(c.in, now)
+		if o != c.expected ||
+			(err == nil && c.expectedErr) ||
+			(err != nil && !c.expectedErr) {
+			t.Errorf("wrong value for '%s'. expected:'%s' got:'%s' with error: `%s`", c.in, c.expected, o, err)
+			t.Fail()
+		}
+	}
+}
+
+func TestParseTimestamps(t *testing.T) {
+	cases := []struct {
+		in                        string
+		def, expectedS, expectedN int64
+		expectedErr               bool
+	}{
+		// unix timestamps
+		{"1136073600", 0, 1136073600, 0, false},
+		{"1136073600.000000001", 0, 1136073600, 1, false},
+		{"1136073600.0000000010", 0, 1136073600, 1, false},
+		{"1136073600.00000001", 0, 1136073600, 10, false},
+		{"foo.bar", 0, 0, 0, true},
+		{"1136073600.bar", 0, 1136073600, 0, true},
+		{"", -1, -1, 0, false},
+	}
+
+	for _, c := range cases {
+		s, n, err := ParseTimestamps(c.in, c.def)
+		if s != c.expectedS ||
+			n != c.expectedN ||
+			(err == nil && c.expectedErr) ||
+			(err != nil && !c.expectedErr) {
+			t.Errorf("wrong values for input `%s` with default `%d` expected:'%d'seconds and `%d`nanosecond got:'%d'seconds and `%d`nanoseconds with error: `%s`", c.in, c.def, c.expectedS, c.expectedN, s, n, err)
+			t.Fail()
+		}
+	}
+}